I am not suggesting a replacement but rather adding an alternative option so both Alt+. and Ctrl+H work. This mostly applies to Dolphin but I also suggest it for any dialog popups as well.

Ctrl+H is the most common shortcut used in a large variety of Linux distros so this would make it available for those people switching to Plasma that expect it to be there.

There currently is an alternative of "F8" but this is so uncommonly used I forgot this was a thing. So I suggest replacing F8 with Ctrl+H as the alternative.

Side Note: I much prefer Alt+. so this is suggestion is to improve onboarding to Plasma, not related to my preference.